WordPress founder Matt Mullenweg has spoken out in an attempt to capitalize on Yahoo's rumored $1.1 billion acquisition of rival blogging service Tumblr. He claims that once the news broke on Sunday, blog post transfers from Tumblr to his own site rose from 400 to 600 per hour to over 72,000 -- which presumably included users put off by Yahoo's track record of shutting down its acquisitions (like Del.icio.us, Geocities and Broadcast.com). If that figure is true, then Marissa Mayer's probably going to have to answer some rather awkward questions in a few hours.